Illumination units for LCD displays comprising luminescence diode chips generally have a plurality of prefabricated luminescence diode chip components within which a luminescence diode chip is respectively enclosed by housing material. The optical waveguide is present as a separate part. It is positioned relative to the luminescence diode component in such a way that light coupled out from the component impinges on a coupling-in area of the optical waveguide.
A precise alignment of the optical waveguide relative to the luminescence diode chip of the luminescence diode component is technically complicated. Moreover, reflection losses occur in the course of coupling into the optical waveguide at the coupling-in area.